As this is an area in which I have more than just a passing interest, I found this recent survey reported on by japan.internet.com and conducted by goo Research into the matter of mobile phone software upgrades most interesting.

Demographics

Between the 21st and 24th of March 2008 1,090 members of the goo Research monitor panel completed a private internet-based questionnaire. 53.8% of the sample was male, 17.2% in their teens, 19.4% in their twenties, 15.6% in their thirties, 17.3% in their forties, 18.4% in their fifties, and 12.0% aged sixty or older.

I suspect my phone is set to manual mode for update notification; my wife, however, had random power-offs when writing mail that I thought may be due to a wonky keyboard, but there had been a software update for the phone, so she downloaded that update and the problem went away.

The low percentage of those with software bugs is due to Japanese quality, where quality is defined as performance to specification. Some specifications are terrible, and the implementation is similarly sometimes suspect, but everything usually works as defined.